Construction and Testing of Deep Foundation Improvement Using the Deep Cement Mixing Method

The construction of an office building (hereafter referred to as “Building N”) was planned in Kagoshima City in western Japan. The building site consisted of loose, alluvial sand called Shirasu, which is subject to liquefaction during earthquakes. It was decided that a newly developed soil improvement technique would be adopted as the foundation construction method. The technique employs the Deep Cement Mixing Method to construct a grid of hardened soil. This grid controls the generation of excess pore water pressure by reducing the occurrence of shear deformation in the native soil within the grid, thereby preventing liquefaction during earthquakes.

This paper discusses the design and construction of the improved soil foundation for Building N.